Electric-arc lamp.



N0. 823,958. PATENTED JUNE 19, 1906. B. J. MURPHY.

,ELSUTRIG ARC LAMP.

APPLiGATIOR FILED SEPT. 9. 1904.

Wimesses lnvenrot Enwm J. MURPHY.

M W @ilgi fl UNITED STATES PATENT OFFICE.

EDWIN J. MURPHY, OF RUGBY, ENGLAND, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECLI'FHC-AFIO LAMP.

No. 823L958.

Specification of Letters Patent.

Patented June 19, 1906.

Application filed September 9, 1904. Serial No. 223,843.

To all whom it may concern.-

Be it known that I, EDWIN J. MURPHY, a citizen of the United States, residing at Rugby, in the county of Warwick, En land, have invented certain new and uscfu Im rovements in Arc-Lamps, of which the fol owing is a specification. 1

This invention relates to arc-lam s, and particularly to lamps arranged for t e production of light from two or more electric arcs connected in series across constant-potential mains.

The common practice heretofore in the design and construction of lamps having two or more sets of electrodes connected in series for use on constant-potential circuits has been to provide the lamps with means whereby after a definite period of operation the movable electrodes are held against further movement until the arcs increase in length so much that they snap, and thus open the circuit, whereupon the movable electrodes drop into engagement with the stationary electrodes and new arcs are struck. By causing the circuit through the lamps to break in this we. before" the electrodes are fed the points of t e eiec trodes of each set are separated by approximately equal distances, excessive variations in the consumption of the electrodes of the several sets are largely prevented, andthe operating mechanism of the lampis eatly sun lifie since both or all the movable electro so are acted on as a unit.

My invention relates to an arc-lamp of this t pehaving means for opening the circuit through the lamp before feeding the electrodes. The means which I employ is an electromagnetic etc which arrests the movement of the electro e-positionin mechanism when in a definite relation and he do it against movement until the circuit is broken. This electromagnetic stop preferabliy consists of a plate of magnetic material bri ing the poles of the core of the actuating-so enoids or cooperating with the armature of the operatingmagnets in a magnet type of lamp. The

plate is held to the core or armature until the movable electrodes have been fed forward a definite amount, when it engages the top of the solenoids or some other member mounted stationarily in the lam and prevents further feeding of the electro es until the circuit is broken, when, of course, the solenoids ormagnets are denergized and the plate released from the coreor armature.

The novel features of my invention will be pointed-out with particularity in the append ed claims.

The details of construction and the mode of operation of m improved arc-lamp will be better understoo by reference to the following description, taken in connection with the accompanying drawing, which shows diagrammatically the preferred embodiment of my invention.

Referring to the drawing, 1 1 indicate solenoids, and 2 a U-sha ed core or armature the legs of which exten Within the solenoids. Suspended from core 2 is a bracket 3, to which are secured the vertical] -adjustable connecting-rods 4 4, and ivotallgr connected to these rods are the ew s 5 5, which at their 0 posits ends are pivoted in ears on the c utch ringsfi 6 for the movable electrodes.

In the drawing two sets of electrodes are shown, but it is evident that employed, if desired.

7 indicates a gas-cap in which are insulating-bushings 8 8, through which the movable electrodes 9 9 extend and on which the yokes 6 Bimpinge to trip the clutches, and thus aliow the electrodes 9 9 to drop into engagement with the stationary electrodes 10 10 Secured to the ends of the legs ofthe U- shaped armature or core 2 are extensions 11 11 of steel, iron or other material which has magnetic pro erties, but which preferably is less permeab e than the material of core 2, and in the ends of these extensions are the guide-pins 12 12, of brass or other non-magnetic material. Resting on the ends of the extensions 11 31 of the core or armature 2 and arranged to slide readily on the pins 12 12 is a pla terer auxiliary armature 13, of iron or other material of good permeability, which constitutes the magnetic stop. A portion of the flu from the coils 1 1 threads the exten- .sions 11 11 and the plate 13, so that the latter is held down upon the ends of the extensions with considerable strength. A dash-pot 19 is secured to the pins 12 I2 and to a stationary portion of the lamp or in any other suitable relation to dampen the movements of core 2.

Circuit through the lamp is completed from the positive main 14 through a cut-out more may be ICC switch 15, a resistance 16, and through the solenoids 1 1 in seri s to one of the movable electrodes 9. The stationary electrode thus limit'the downward movement.

corresponding thereto is connected to the movable electrode of the other pair, and the stationary electrode of that pair is connected to the negative main 18. The drawing shows the position of the parts just after the arcs have been struck. As the electrodes are consumed the core 2 falls gradually, permitting the movable electrodes to appror ch the stationary electrodes to maintain a con stant length of the rrcs. After the lamp has been in operation for in interval the core 2 falls enough to bring the plate 13 into eng. gement with the tops 17 of the spools of the solenoids 1 l. The flux passing from the legs of the core 2 through the extensions 11 1 1 and through the plate 13 holds the core to the plate with sufficient strength to prevent any further drop, and hence the movable electrodes 9 9 are held against'further downward movement. The arcs therefore increase in length as the electrodes 2" re consumed,until finally the drop in volts ge across the arcs-is so great that they are snapped and the circuit broken. The solenoids 1 1 re thus deenergized, plate 13 is released from the extensions 11 11, and core 2 falls by gravity, so that the yokes 6 6 hit upon the bushings 8' 8 or any other suitable tripping-platform and theclutches are tripped. As the core 2 falls the pins 12 12 slide looselv through the openings in plate 13 until the heads of the pins catch upon the plate 13, P nd The clutches being tripped permit the movable electrodes 9 9 to fall into engcgement with the stationary electrodes 10 10, and as this closes the circuit again the solenoids re ise core 2 and the core raises plate 13, so that all parts are again in the position illustrated. It will thus be seen that the circuit is interrupted only momentarily when feeding of the electrodes is necessary, that both arcs ere struck simultaneously, so that they are at all times approximately equal in length, and that a single mechanism positions both of the movable electrodes.

I have illustrated and described herein an arc-lamp having two or more sets of electrodes therein operated by a single feeding mechanism of the solenoid type; but I do not wish to be understood as limited in this respect. The

principles of my invention are also applicable l to lamps having mi gnets to opera te the electrode-positioning devices instead of the solenoid type of lamp shown or to lamps in which distinct feeding devices are used for the several arcs. All such modifications of the construction herein shown I consider within the scope of m invention, and I aim to cover them in the c aims appended hereto.

What I claim is new, and desire to secure by Letters Patent of the United States, is

1. A twin-arc lamp having a plurality of movable electrodes, an electromagnetic winding and a core or armature therefor for positioning the movable electrodes, and a member made of magnetic material adapted to be acted upon ms gneticslly by s id winding to arrest the movement of the electrode-positioning mechanism when in a definite position.

2. A twin-arc lamp havingla plurality of movable electrodes, a solenoid*] coil and an r rm; ture cooperating therewith for positioning the electrodes, 2 nd an auxiliary armature movably mounted in proximity to said armature and adapted to be actuated by the flux of sid coil to arrest the movement of s"id armature when the letter has reached a definite position.

3. An arc-lamp having a movable electrode, two solenoid-coils and a U-shaped core cooperr ting therewith for positioning the electrode, and en auxilis ry armature mounted in proximity to the legs of sid core'and adapted when attracted to arrest the movement of the core when the latter hasreached a definite position.

4. An arc-lamp having a movable electrode, a pair of solenoids and a -U-shaped core therefor for positioning the electrode, and an auxiliary armature adapted to bridge the ends of the legs of said U-shaped core and to impinge on the ends of the solenoids.

5. In an arc-lamp, two solenoid-coils, a U- sheped core, the legs of which extend through sriid coils, guide'pins in the ends of said legs, and a plate of magnetic material loosely mounted on said pins and adapted to bridge the ends of the legs of said core.

6. In an arc-lamp, two solenoid-coils, a U- shaped core, the legs of which extend within the coils, extensions on the ends of said le of material which is less permeable than that of the core, guide-pins in the ends of said extensions, and a plate of magnetic material loosely mounted on said pins and adapted to bridge the ends of said extensions.

In witness whereof I have hereunto set my hand this 24th day of August, 1904.

EDI VIN J. MURPHY.

Witnesses:

JOHN GRAY, ll. CLAY EVANS.

IIO 

